Abstract: Microtransit services offer a potential way to improve accessibility in rural areas where traditional fixed-route transit systems are challenging to run efficiently. This study introduces a shared microtransit optimization model which is designed to evaluate performance under different goal priority structures. The model balances passenger travel requests and operational efficiency. Its three primary goals are to minimize unserved ride requests, reduce excess passenger travel time, and minimize total vehicle operational cost overrun. Operating over discrete time steps, the model assigns passengers based on origin-destination requests, pickup time windows, and vehicle capacity constraints.  The model is tested in rural, small city, and large urban service environments to understand how different operating conditions influence results. Several goal priority scenarios are compared to assess their ability to satisfy both passenger and provider goals. The findings support transit agencies and planners in selecting goal priorities and managing trade-offs among service, passenger travel time, and operational cost.